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Numeration and type synthesis of 3-DOF orthogonal translational parallel manipulators

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Progress in Natural Science:Materials International 2008年第5期18卷 563-574页

作者： Jingjun Yua, Jian S. Dai b, Shusheng bi a, Guanghua Zong a a Robotics Institute, beihang University, beijing 100083, china b department of mechanical Engineering, School of Physical Science and Engineering, King’s College, University of London, The Strand, London WC2R 2LS, UK Robotics Institute Beihang University Beijing 100083 China department of mechanical Engineering School of Physical Science and Engineering King’s College University of London The Strand London WC2R 2LS UK

Low-degree-of-freedom (Low-DOF) parallel manipulators (PMs) have drawn extensive interests, particularly in type synthesis in which two main formal approaches were established by using the reciprocal screw system theory and Lie group theory. This paper aims at numeration and type synthesis of orthogonal translational parallel manipulators (OTPMs) by resorting to an integration of the group- based method and graphical representation of the topology. For this purpose, the concept of Cartesian DOF-characteristic matrix, orig- inated from displacement subgroup and displacement submanifold, is proposed. A new approach based on the combination of the atlas of Cartesian DOF-characteristic matrix and the displacement group-theoretic method is addressed for both exhaustive classi cation and type synthesis of OTPMs. The proposed approach is prone to construct an orthogonal structure and is easy to realize the complete clas- si cation and exhaustive enumeration of this class of low-DOF PMs.

关键词： Type synthesis Displacement group Orthogonal translational parallel manipulator

An improved group search optimizer for mechanical design optimization problems

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Progress in Natural Science:Materials International 2009年第1期19卷 91-97页

作者： Hai Shena,b,c,Yunlong Zhu a,ben Niu a,b,Q.H.Wu d a Key Laboratory of Industrial Informatics,Shenyang Institute of Automation,Chinese Academy of Sciences,Shenyang 110016,china b Graduate School of the Chinese Academy of Sciences,beijing 100049,china c College of Physics Science and Technology,Shenyang Normal University,Shenyang 110034,china d department of Electrical Engineering and electronics,The University of Liverpool,brownlow Hill,Liverpool,L69 3GJ,UK [a]Key Laboratory of Industrial Informatics Shenyang Institute of Automation Chinese Academy of Sciences Shenyang 110016 China [b]Graduate School of the Chinese Academy of Sciences Beijing 100049 China [c]College of Physics Science and Technology Shenyang Normal University Shenyang 110034 China [d]Department of Electrical Engineering and Electronics The University of Liverpool Brownlow Hill Liverpool L69 3GJ UK

This paper presents an improved group search optimizer(iGSO) for solving mechanical design optimization *** the proposed algorithm,subpopulations and a co-operation evolutionary strategy were adopted to improve the global search capability and convergence *** iGSO is evaluated on two optimization problems of classical mechanical design:spring and pressure *** experimental results are analyzed in comparison with those reported in the *** results show that iGSO has much better convergence performance and is easier to implement in comparison with other existing evolutionary algorithms.

关键词： mechanical optimization problem GSO Constrained optimization problem

Microstructural characterization of the Al/Cu/steel diffusion bonded joint

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Rare Metals 2009年第5期28卷 478-481页

作者： bAI bingzhe GAO Yimin FENG Chun Laboratory of Advanced Materials Department of Materials Science and Engineering Tsinghua University Beijing 100084 China State Key Laboratory for mechanical behavior of Materials School of Materials Science and Engineering Xi＇an Jiaotong University Xi＇an 710049 China

A vacuum hot-pressed diffusion method was used to prepare an Al/Cu/steel composite with a gradient structure. The Al/Cu interface was investigated layer by layer by means of scanning electron microscopy, energy dispersive X-ray spectrometry, electron probe microanalysis, and Vickers microhardness. The results show that two kinds of intermetallic compounds, Cu9Al4 adjacent to the Cu side and CuAl2 adjacent to the Al side, are formed in the interface of Al/Cu. The conductivity is 0.369 mS/cm in the intermetallic compound with a thickness of 3.5 μm, higher than that of the intermetallic compound with a thickness of 23 μm, in which the conductivity is 0.242 mS/cm.

关键词： metal composites diffusion bonding intermetallic compounds microhardness interface

Numerical Simulation of Macrosegregation During Steel Ingot Solidification Using Continuum Model

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Journal of Shanghai Jiaotong university(Science) 2011年第2期16卷 145-148页

作者：王励石伟 Key Laboratory for Advanced Materials Processing Technology Ministry of Education department of mechanical Engineering Tsinghua University

A continuum model is adopted to study the macrosegregation phenomena during solidification of large steel *** of temperature,melt velocity,and compositional concentration field during a 22 t steel ingot solidification are illustrated by using the finite volume *** results of temperature distribution are validated by *** influence of local permeability relates to the friction that the melt experienced in mushy region is *** is shown that the continuum model is able to predict the temperature field,and the variation of permeability obviously affects the melt flowing behavior and the final compositional distribution.

关键词： continuum model steel ingot macrosegregation convection permeability

Efficient generation of two-dimensional cluster states in a cavity QED

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Chinese Physics b 2013年第4期22卷 124-127页

作者：张刚周建薛正远 Machinery and electronics Engineering Institute West Anhui University Anhui Xinhua University Laboratory of Quantum Information Technology and School of Physics and Telecommunication Engineering South China Normal University

We propose a scheme to achieve a kind of nontrivial multipartite pair-wise controlled phase operation in a cavity QED setup. The operation implemented is of geometrical nature and is not sensitive to the thermal state of the cavity. In particular, we have managed to avoid the conventional dispersive coupling so that high speed gate operation is achieved which is very important in view of decoherence. We show that this multipartite pair-wise controlled phase operation makes the generation of two-dimensional cluster states very efficient.

关键词： controlled phase gate cluster state cavity QED

Ultralight X-type lattice sandwich structure (Ⅱ):Micromechanics modeling and finite element analysis

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Science china(Technological Sciences) 2009年第9期52卷 2670-2680页

作者： ZHANG QianCheng1,CHEN AiPing 2,CHEN ChangQing2,3 & LU TianJian2 1 State Key Laboratory for mechanical behavior of Materials,School of Material Science and Engineering,Xi’an Jiaotong University,Xi’an 710049,china 2 MOE Key Laboratory for Strength and Vibration,School of Aerospace,Xi’an Jiaotong University,Xi’an 710049,china 3 department of Engineering Mechanics,AML,Tsinghua University,beijing 100084,china State Key Laboratory for mechanical behavior of Materials School of Material Science and Engineering Xi’an Jiaotong University Xi’an China MOE Key Laboratory for Strength and Vibration School of Aerospace Xi’an Jiaotong University Xi’an China department of Engineering Mechanics AML Tsinghua University Beijing China

The methods of homogenization and finite elements are employed to predict the effective elastic constants and stress-strain responses of a new type of lattice structure,the X-structure proposed by the authors in a companion paper. It is shown that in most cases the predictions by the equivalent homogenization theory agree well with the experimental and 3-dimensional finite element calculated results. The theoretical and numerical study supports the argument that the X-structure is superior to the pyramid lattice structure in terms of mechanical strength.

关键词： sandwich panel lattice structure equivalent homogenization finite element model

Anticoagulation property and security of artificial heart valve material

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Science china(Technological Sciences) 2005年第2期48卷 145-162页

作者： WANG Xianghui1, , LIU Xianghuai1,22, 3, ZHANG Feng2, LI Changrong2, YU Liujiang2, ZHENG Zhihong2, WANG Xi2, JIANG Zhenbin4, CHEN Anqing4 & XU Jingfang3 1. department of Physics, East china Normal University, Shanghai 200062, china 2. Ion beam Lab, Shanghai Institute of Mini-system and information, Chinese Academy of Sciences,Shanghai 200050, china 3. department of electronics, School of Information Science and Technology, East china Normal Univer- sity, Shanghai 200062, china 4. Shanghai Cardiovascular Institute, Zhongshan Hospital, Shanghai 200032, china 1. department of Physics East China Normal University 200062 Shanghai China 2. Ion beam Lab Shanghai Institute of Mini-system and information Chinese Academy of Sciences 200050 Shanghai China 3. department of electronics School of Information Science and Technology East China Normal University 200062 Shanghai China 4. Shanghai Cardiovascular Institute Zhongshan Hospital 200032 Shanghai China

Heart valve diseases threaten human health. One reliable way to save lives of such patients is to replace the pathologically changed heart valves by artificial ones. Over 2 million patients have received LTI-carbon heart valve’s implantation. However, the thrombosis after the implantation is one of the difficulties that need to be solved. In order to improve the blood compatibility and security of mechanical heart valves, ion beam technology was used to modify the surface properties of the materials. The investigation results have been summarized in this paper.

关键词： artificial heart valve, ion implantation, plasma immersed ion implantation, ion beam enhanced deposition.

SINGULAR bEHAVIORS OF INTERFACIAL CRACKS IN 2D MAGNETOELECTROELASTIC bIMATERIALS

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Acta Mechanica Solida Sinica 2009年第3期22卷 232-239页

作者： Cuiying Fan1 Youhe Zhou1 Han Wang2 Minghao Zhao1,2(1Key Laboratory of Mechanics on Disaster and Environment in Western china,the Ministry of Education of china,and department of Mechanics and Engineering Science,College of Civil Engineering and Mechanics,Lanzhou University,Lanzhou 730000,china)(2School of mechanical Engineering,Zhengzhou University,Zhengzhou 450001,china) [a]Key Laboratory of Mechanics on Disaster and Environment in Western china the Ministry of Education of China and Department of Mechanics and Engineering Science College of Civil Engineering and Mechanics Lanzhou University Lanzhou 730000 China [b]School of Mechanical Engineering Zhengzhou University Zhengzhou 450001 China

The singular characteristics of stress,electric displacement and magnetic induction fields near the tip of impermeable interfacial cracks in two-dimensional magnetoelectroelastic bimaterials are studied using the generalized Stroh *** types of singularities are ob-tained:one is the oscillating singularity 1/2±iε,the other is the non-oscillating singularity 1/2±κ.It is found that the non-zero parameters ε and κ cannot coexist for one transversely isotropic MEE bimaterial,a similar result is obtained for transversely isotropic piezoelectric bimaterials.

关键词： generalized Stroh formalism magnetoelectroelastic bimaterial interfacial crack singularity index

Visible Light Induced Photocatalysis of Cerium Ion Modified Titania Sol and Nanocrystallites

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Journal of Materials Science & Technology 2004年第1期20卷 14-18页

作者： Yibing XIE and Chunwei YUANKey Laboratory of Molecular & biomolecular electronics, Southeast University, Ministry of Education, Nanjing 210096, china Southeast Univ Key Lab Mol & Biomol Elect Minist Educ Nanjing 210096 Peoples R China

The cerium ion(Ce4+) doped titania sol and nanocrystallites were prepared by chemical coprecipitation-peptization and hydrothermal synthesis methods, respectively. The X-ray diffraction pattern shows that Ce4+-TiO2 xerogel powder has semicrystalline structure and thermal sintering sample has crystalline structure. Ce4+-TiO2 nanocrystallites are composed of the major anatase phase titania (88.82 wt pct) and a small amount of crystalline cerium titanate. AFM micrograph shows that primary particle size of well-dispersed ultrafine sol particles is below 15 nm in diameter. The particle sizes are 30 nm for xerogel sample and 70 nm for nanocrystallites sample, which is different from the estimated values (2.41 nm and 4.53 nm) by XRD Scherrer's formula. The difference is mainly due to aggregation of nanocrystallites. The experimental results exhibit that photocatalysts of Ce4+-TiO2 sol and nanocrystallites have the ability to photodegrade reactive brilliant red dye (X-3b ) under visible light irradiation with the ion-TiO2/VIS/dye system. Moreover, Ce4+ doped titania sol has shown higher efficiency than the nanocrystallites sample in respect of potocatalytic activity. Meanwhile, dye photodegradation mechanisms are proposed to different photocatalytic reaction systems, which are dye photosensitization, ion-dye photosensitization and interband photocatalysis & dye photosensitization with respect to TiO2 nanocrystallites, Ce4+-TiO2 sol and Ce4+-TiO2 nanocrystallites system.

关键词： Photocatalytic activity Sol Nanocrystallites Photosensitization Reaction mechanism